In recent years, white LED (Light Emitting Diode) has been put into practical use as a high-efficiency illumination light source, in place of incandescent and fluorescent lamps. White LED is adjusted to daylight white or warm white by combining a blue LED element and a yellow phosphor, and as the case requires with e.g. a red phosphor. In order to protect the LED element and the phosphor from the physical and chemical actions from the outside, the light emitting element is sealed with a transparent resin such as a silicone resin.
As such a transparent resin for sealing LED, a cured product has been proposed which is obtained by curing a curable fluorinated polymer having carboxylic acid alkyl ester groups such as COOCH3 groups, by irradiation with active energy rays, and which is excellent in stability with less generation of HF (Patent Document 1).